This invention relates generally to multimode electronic timepieces. More particularly, the invention relates to an improved program adapted to display a mode which comprises a plurality of submodes of the timepiece, such as chronograph and countdown timer.
Multimode, multifunction wristwatches (or wrist instruments) are known which include a display, a lamp for illuminating the display, a number of manually actuated switches and an integrated circuit programmed in a preselected sequence. Examples of such watches are seen in U.S. Pat. No. 4,783,733-Houlihan et al., U.S. Pat. No. 4,780,864-Houlihan and U.S. Pat. No. 4,283,784-Horan, all of the foregoing being assigned to the present assignee. In the Horan patent, a timepiece is provided with an integrated circuit, including a main random access memory (main RAM), a flag random access memory (flag RAM) and a programmed logic array (PLA), which are efficiently disposed in the timepiece such that a minimum amount of semiconductor chip space is used. The combination of these elements is adapted so as to provide for greater flexibility for operator selection of one of the plurality of timekeeping functions, or modes. In the foregoing Houlihan patents, which are merely exemplary of multimode electronic wrist instruments or multifunction wristwatches, one of the manual actuators may typically serve to repetitively cycle the instrument through a number of modes and operating states in each of which a different type of information is displayed. Such modes may include, in a multifunction watch, the time of day, chronograph, dual time zone, countdown timer and so forth. By special preselected actuation of one of the actuators, the wristwatch may be converted into a computer, a speedometer, pulsometer or any other type of device, subject only to the imagination of the designer and programmer of the integrated circuit. While in any of these modes, another manual actuator may be employed to change the information being displayed in that mode's state, such as initiating the chronograph timing or setting the time-of-day, or performing a calculation.
Timepieces are known wherein actuation of different preselected actuators will cause the timepiece to be disposed into distinct and separate modes, and which are adapted to perform distinct and separate functions. Such examples include U.S. Pat. No. 4,887,249, Thinesen, Bicycle Watch--Dual Mode Circuit (Dec. 12, 1989) and U.S. Pat. No. 5,050,141, Thinesen, Program to Synchronize Pace in a Multimode Alarm Timepiece (Sep. 17, 1991), both of which are assigned to the present assignee. The former discloses a dual-mode digital wristwatch which is adapted to operate in a "watch mode," displaying such information as time-of-day and date, but can also be adapted to operate in a "bike mode," serving as a computer to display such information as speed, distance andpedaling cadence. The latter discloses a program to synchronize and display the pace of an operator, and includes other modes such as time-of-day mode and chronograph/countdown timer mode, wherein each mode is adapted to display various operating states through the manual actuation of a plurality of actuators.
Although it is possible to provide a multimode electronic timepiece with sufficient memory so that calculations necessary for each of a timepiece's timing subroutines may be performed simultaneously and continuously, it is often desirable to provide the timepiece with less memory in order to reduce the cost of the timepiece and to concomitantly conserve timepiece physical space which is limited. One way to achieve this result is to provide the timepiece with a microcomputer which is adapted to provide some of the timepiece's timing subroutines using the same random access memory (RAM) space such that these timing subroutines can only be operated in a mutually exclusive manner. That is, after the operator selects one of the timing subroutines, such as chronograph or countdown timer, certain memory storage locations of the RAM become solely dedicated to storing those values determined by calculations specific to the chosen timing subroutine. None of these same memory storage locations of the RAM storage is then dedicated to the storage of values of any of the other timing subroutines, and these other subroutines are therefore inactive; i.e., there is no continuous and systematic update of the values of a timing subroutine which has not been selected by the operator.
A problem with such timepieces is that after the operator selects one of these mutually exclusive timing subroutines, thus entering one of its operating states, he is not precluded from selecting an operating state of any other of the mutually exclusive timing subroutines. Confusion of the operator will result, if he accidentally actuates an actuator that is dedicated to one of the mutually exclusive timing subroutines which is currently inactive, because as the calculations necessary to the inactive subroutine are not being continuously and systematically updated, the value displayed will not represent the true and correct value of the operating state of that inactive timing subroutine. Thus it is also desirable to provide a timepiece with mutually exclusive timing subroutines wherein selection of one timing subroutine will preclude the selection of any other timing subroutine while in any operating state of the chosen timing subroutine.
Accordingly, one object of the present invention is to provide a multimode electronic timepiece with reduced random access memory means for storing values for mutually exclusive timing subroutines (or mutually exclusive submodes)
Another object of the present invention is to provide an improved program which is adapted to provide a mode which comprises a plurality of submodes of the timepiece where selection of one of the submodes will preclude the selection of the other submodes while the timepiece is disposed in any of the operating states of the chosen submode.
Still another object of the present invention is to provide an improved program which precludes the operator from determining the status of any of the operating states of a submode other than that of the currently selected submode.
Yet another object of the present invention is to provide an improved program which is adapted to provide the timepiece display with a mode having a display of the mutually exclusive submodes.